The black flag of Somali terror group Al-Shabaab flies on Twitter - and its tweets are in English - English that reads like it is written by a native speaker.

It’s not known who the writer is - but over the last five years there have been mounting questions over the number of people from the UK who have been going to Somalia to help Al-Shabaab, an organisation affiliated to Al-Qaeda that controls part of the country.

This spring, those concerns have been focused on the case of East Londoner Jermaine Grant. He is accused in Kenya of being part of a bomb plot orchestrated by the Islamist movement.

Grant, already convicted of entering the country illegally, denies involvement in a plot and his lawyers say he has been beaten and subjected to solitary confinement.

But it's now emerged that Samantha Lewthwaite, the widow of 7/7 bomber Jermaine Lindsay, is wanted in connection with the same alleged bomb plot for which Jermaine Grant is now on trial.

Investigators suspect the two worked together and that Ms Lewthwaite was the "financier". She is missing from Kenya and has not been formally charged.

The alleged link to 7/7 (which involved terror blasts in London) is the starkest example yet of why the British security and intelligence agencies are so worried about Britons in Somalia.

The ringleader of the 7/7 bombers, Mohammad Sidique Khan, began his journey to a violent end by rattling buckets raising cash for Kashmir. He then went to Pakistan for mujahideen training and, much later, brought his war back to the UK.